Bottom hole well plug



June 25, 1935. Q MAGUIRE ET AL 2,006,105

BOTTOM HOLE WELL PLUG Filed Dec. 12, 1.934

Inventors Attorney Patented June 25, 1935 UNITED STATES PATENT OFFICE BOTTOM HOLE WELL PLUG Application December 12, 1934, Serial No. 757,201

' 1 Claim.

This invention relates to a unique device adapted to be used in conjunction with present day lead filling method to cooperate therewith in providing a more effective leak-proof seal for an oil well, and as the title implies, it is more in the nature of what may be conveniently defined as a bottom hole well plug.

It is well known that difierent pay sands, in the lime formation especially, exist one above the other with water immediately below. It very often happens that in drilling, a well is put through to the water and the necessity arises for plugging back, or it might be that the lower pay exhausts itself of oil and turns to water, and then it is necessary to plug oif that particular strata.

The present method of doing this is by a combination of pounding in lead slugs and lead wool, but where the water pressure from below is great, as it usually is, it is very hard to get a perfect seal with lead and lead wool due to the enormous pressure from below that forces the plug out of the hole, or moves it sufiiciently to cause a leak.

The present invention has to do with an ingenuous two-part hole plugging device usable in connection with the aforesaid lead slugs and lead wool in such a way as to cooperate therewith in providing a more successful and dependable closure for the bottom hole of the well.

structurally, the plug proper is in the nature of a radially expansible split casing or spool having coordinated therewith a sturdy wedge forming conical expander susceptible of being driven home by readily available well equipment so as to firmly anchor the plug in the surrounding hard limestone or cap rock.

Other more specific features and advantages will become more readily apparent from the following description and drawing.

In the drawing:

Figure 1 is a top plan view of a device constructed in accordance with the principles of our present invention.

Figure 2 is an elevational View thereof with 45 the plug and expander assembled for use.

Figure 3 is a section taken approximately on the plane of the line 3--3 of Figure 1.

Figure 4 is a view at right angles to Figure 2, a portion of the wedge or expander being broken away for clearness of illustration and conservation of space.

Figure 5 is a bottom plan view of the hollow expansible hole closing plug.

An essential part of the invention, as before indicated, is hereinafter variously referred to, as a unit, under the name of a plug, a casing or.a tampion. For convenience however, it is broadly referred to as a plug and differentiated by the numeral 6. As shown in Figure 3 it is formed in its bottom with a cylindrical cavity or socket I 5 and at its top and bottom with outstanding annular flanges. Therefore, it is in the nature of a hollow spool. At diametrically opposite points it is formed with slits 8 which extend from the top down to but terminate short of the base 10 flange. Consequently, the base flange 9 serves as a tampion and packing head. It is sufiiciently solid or rigid to satisfactorily accomplish this function. The slit of course, divides the plug into half sections and also divides the top flange ID 15 into similar complemental sections. These stand out sufficiently to be imbedded, when spread, in the hard surrounding wall of limestone or cap rock.

The cross sectional diameter or proportions of the plug will depend largely on the size of the hole in which it is inserted for packing and closing purposes.

The wedge or expander unit is denoted by the numeral ll. It comprises a sturdy body including a frusto-conical body 42 which joins with the upper cylindrical head portion l3 through the instrument-ality of a shoulder forming endless annular rib M. The head, it will be observed, is provided with threads or equivalent elements 15 which serve to provide a tool grip for lowering the plug into the hole and properly setting same. The lower tapered end extends down into the spool through a passage 16 where it enters the socket or cavity '1. Normally, this end portion is anchored in said tapered hole by way of a soft steel connecting pin H which goes through the plug at right angles to the slits B.

The method of using this device is in connection with a lead plug. After a lead plug has been put in the hard shell or cap rock between the pay strata, the bottom of which is the one to be shut 01?, the device is then put down on top of the lead and the regular tools are used to drive the mandrel down into the casing. The casing or plug proper being split up the sides, the mandrel spreads the top section and drives the edges back into the hard limestone or cap rock. Additional slugs of lead or lead wool are then tamped on top of it and a perfect seal is the result. The hole can then be bailed out and put to producing in the upper pay strata.

Our invention is to be used in connection with lead plugs or other sealing substance and could be entirely enclosed in lead by melting the lead around it up to the rib in the mandrel.

The gist of the invention resides in the provision of a metallic spool-like plug or tampion having an annular base flange and a cylindrical body. Said body being of hollow construction and formed with diametrically opposed slits in the upper end portion thereof having a tapered hole to accommodate the expander and outstanding segmental flanges to bite and become imbedded in the surrounding wall of limestone or cap rock when radially expanded. In addition, the wedge or expander unit is ingenuous in that it is properly constructed for cooperation with the tapered bore or passage in the upper part of the expansible spool. It is properly attached thereto by a suit-v able soft steel pin ll. The upper head end of the wedge is fashioned to receive the impact or blows from the regulation tools for driving the wedge home. All of these features are reflected in the drawing and are hereinafter covered in divers ways in the accompanying claim.

It is thought that persons skilled in the art to which the invention relates will be able to obtain a clear understanding of the invention after considering the description in connection with the drawing. Therefore, a more lengthy description is regarded as unnecessary.

Minor changes in shape, size and rearrangement of details coming within the field of invention claimed may be resorted to in actual practice, if desired.

Having thus described our invention, what we claim as new is:

As a new article of manufacture, a cylindrical spool-like body adapted to function as a well closing plug, said body being formed at its bottom with an outstanding annular base flange and formed at its top with a corresponding type anchoring flange, said body having a socket in its bottom and a communicating tapered bore in its top, diametrically opposed portions of said body being formed with longitudinal slits extending through the top flange down to and terminating short of the base flange to allow the slit portion to expand radially for anchorage purposes.

CHARLES L. MAGUIRE. GARNETI HADLEY. 

